I was having a conversation about DnD and Med Faire and such, and I had the recollection of a brief LARP campaign my group and I did one year way back in the day.
There were five of us in all for regulars, but sometimes we'd have situations where we'd meet another small group, two or three, who would join every now and again. This was one of those situations, and we were on some sort of Quest For The Thing. Now... It's a generally understood rule that you never trust the rogue. Even if it's your rogue. Don't trust them.
I was that rogue. It wasn't my first time playing the secret bad guy, so I knew how to play this game pretty well. It took a couple months for them to start to genuinely suspect their teammate was up to no good, and I could start to see them finally beginning to plot. I knew the next time we met up, they would make their move and try to defeat me.
Now, I should take a step back briefly and explain the type of environment we're in. Ozarks, so there's mountains and hills and lots of wilds to actually do things in... And trail riders. Lots and lots of trail riders. See, there was a particular trail riding group in the area that seemed to very much enjoy the same things we do, but never had the courage to approach us and ask to join... I gave them that chance.
When the heroes finally made their decision, they turned against me and ousted me for who I really was. I had my monologue, told them that as much as I've enjoyed watching them grow over the seasons, they didn't stand a chance. I had things to do in this world and gave them one last moment to reconsider their actions. Our six brave heroes, stalwart as they are, advanced against me with their blades drawn, ready for a fight.
I whistled... And eight barbarians on heavy horse came charging over the hill at full speed, weapons drawn and roaring with thirst for battle.
I've never seen a group of heroes disperse so quickly in my life.